My old Yamaha RX-V659's sole oddity was about once a year, it had to have a hard reset. The front L+R channels would go dead and only the center and surrounds would play. The first time it happened, it was just after the warranty had expired and I thought, "Of course, it's dead with no warranty!", and I started shopping for a new AVR, but tried the hard reset and it worked. Of course, the main problem was setting it all up again after losing all the settings. I had kind of the same thing happen with the really nice sounding JVC stereo I had in my truck about 10 years ago. Sirius would be playing, it was always Sirius that caused it, and it would start changing channel numbers but the audio would stay on whatever channel it was originally on. After a minute or so, it would say something like "Error 07" and it was bricked until you did the hard reset. The stereo dealer replaced it but the new one did it too. I finally got fed up with it and sold it, and replaced it with another brand stereo, which didn't sound as good, but didn't drive me nuts with having to reset all the adjustments and the JVC had tons of them. Later on, I found out that my (ridiculed) suggestion to the dealer that it was a power surge was correct and just a big cap would have probably solved it. Oh well. My friend that bought it had no issues with it and loved it.
Hope it works out for you!
